The present invention relates to a cold and hot storage that cools and heats storage material.
Conventionally, a wet towel, for example, a cooled or a heated wet towel is provided for a customer, depending on the season or the temperature in order to improve service for a customer at, for example, a showroom, a hotel, and a restaurant. Generally, a cold and hot storage capable of cooling or heating a wet towel is used in a case of providing a cooled or heated wet towel for a customer. Such a cold and hot storage, which is known, includes: a box-shaped thermal conductor including a metal having good thermal conductivity, such as an aluminum, an aluminum alloy or the like; an electrothermal heater wound around the peripheral wall portion of the box-shaped thermal conductor; a Peltier element in close contact with the bottom portion of the box-shaped thermal conductor; and a heat insulating layer covering the outer periphery of the box-shaped thermal conductor, the electrothermal heater, and the Peltier element. In a case of performing cooling, the Peltier element is energized to cool the box-shaped thermal conductor, and in a case of performing heating, the Peltier element is not energized and only the electrothermal heater is energized to heat the box-shaped thermal conductor by the electrothermal heater (for example, refer to Patent Literature 1).
Patent Literature 1: JP-A-Hei-11-316074
Incidentally, in a case where it is necessary to provide wet towels to many customers, cooling or heating a large number of wet towels simultaneously by a large-sized cold and hot storage is possible. However, in a case where an installation space is limited, it may be difficult to install the large-sized cold and hot storage. Also, in a case of heating the wet towel in the cold and hot storage described in Patent Literature 1, heating of the box-shaped thermal conductor is performed by an electrothermal heater wound around the peripheral wall portion of the box-shaped thermal conductor, and it takes a long time to heat the wet towel because the wet towel housed in the box-shaped thermal conductor is heated by natural convection and heat conduction of the air in the storage. In a case of cooling the wet towel in the cold and hot storage described in Patent Literature 1, the box-shaped thermal conductor is cooled by a Peltier element brought in close contact with the bottom portion of the box-shaped thermal conductor and whereby it takes a long time to cool the wet towel because the wet towel housed in the box-shaped thermal conductor is cooled by natural convection and heat conduction of the air in the storage.
In addition, the box-shaped thermal conductor is heated or cooled so as to heat or cool the wet towels housed in the box-shaped thermal conductor by natural convection and thermal conduction of the air in the storage. Therefore, although the wet towels housed at a position close to the inner wall portion of the box-shaped thermal conductor are heated or cooled in a short time, it takes a very long time to heat or cool the wet towels which are housed in the center portion of the box-shaped thermal conductor while being surrounded by other wet towels.
Therefore, it is desired to develop a cold and hot storage which can rapidly cool or heat all of the wet towels housed in the cold and hot storage without increasing the size of the cold and hot storage. In addition, even when the wet towels are capable of being rapidly cooled or heated, it is preferable that the power consumption is low.
Moreover, in the cold and hot storage described in Patent Literature 1, when cooling is performed, dew condensation occurs between the box-shaped thermal conductor and the heat insulating layer. As a result, the electrothermal heater rusts to disconnect the electrothermal heater, thereby failing to heat the wet towels. In such a case, the electrothermal heater wound around the peripheral wall portion of the box-shaped thermal conductor is covered with the heat insulating layer. Therefore, in order to repair the disconnection point of the electrothermal heater, the heat insulating layer covering the peripheral wall portion of the box-shaped thermal conductor needs to be removed. Accordingly, it is extremely difficult to repair the electrothermal heater.